Insect repellent



United States Patent 3,080,275 INSECT REPELLENT Anthony G. Grady, Chicago, Joseph A. Verdol, Bolton, and Russell W. 'Walker, Lansing, Ill., assignors, by mesne assignments, to Sinclair Research, Inc., New York, N.Y., a corporation of Delaware No Drawing. Filed Feb. 8, 1961, Ser. No. 87,782 Claims. (Cl. 167-22) The present invention relates to the repelling of insects by using certain oxidized petroleum derivatives. According to this invention, it has been found that an alkylate boiling primarily in the range of about 100 to 460 F. when oxidized with a free-oxygen-containing gas, is a very effective insect repellent, particularly for cockroaches.

The alkylate used in the present invention boils primarily in the range of about 100 F. to 460 F. andgenerally has a boiling point spread of at least about 30 F. and preferably at least about 70 F. The alkylate is prepared from an isobutane and a C -C aliphatic monoolefin hydrocarbon by treatment with a catalyst, for instance, an acidic material such as sulfuric acid, hydrotluoric acid or other mineral acids. The products produced by this alkylation process are essentially isoparaffinic in structure and contain few, if any, olefin and aromatic components. The lower boiling components produced by the alkylation process, e.g. those boiling primarily in the range of about 100 F. to 350 F. are widely used in aviation fuels and premium automobile fuels, and are marketed as alkylate gasoline. The alkylate gasoline fractions are suitable for use in preparing the repellent of the present invention. It is preferred, however, to employ the higher boiling fraction of the alkylate product, namely those boiling primarily in the range of about 350 to 460 R, which are known in the petroleum industry as odorless solvents. Odorlezs solvents are currently marketed in two grades diiferening mainly in boiling range. The material marketed as odorless solvent light has an ASTM boiling range of about 345 F. to 395 F. with a 50% point of about 360'F. The odorless solvent heavy has a boiling range of about 375 to 460 F., and a 50% point of about 395 F. The olefin content of these products normally varies from about 1% to 10% and the total paraffin content is normally greater .than about 90%.

The oxidized alkylate product of the present invention ature range employed for oxidation can be from ambient temperatures to the reflux temperatures of the alkylate material employed when conducting the oxidation in the liquid phase. Preferably the temperature is from about to 200 C. If a vapor phase oxidation procedure is employed, then the reaction is, of course, carried out above the boiling point of the alkylate feed and up to just below the decomposition temperature of the feed or product. The amount of oxygen employed in the oxidation scan conveniently range from about 0.05 to 1 s.c.f. liter of hydrocarbon/hour and the reaction is. continued for atleast about 2 up to about 100 or somewhat more hours, preferably about '20 to 40 hours. Longer times can be used but do not seem to improve the product suf- 'ficiently to justify the added expense and inconvenience. The preferred manner .of producing the repellents of the present invention is by non-catalytic liquid phase oxidation of the alkylate materials. ,Catalytically oxidized alkylate is found to be less effective as a repellent than alkylate oxidized in the absence of a catalyst.

The extent of oxidation efiected is preparing the repellent of the present invention is measured by peroxide number. The non-catalytic oxidation is suflicient to provide the oxidized alkylate with a peroxide number of at least about 50, preferably at least about 200 or 400. No reason has been found for carrying the oxidation past a peroxide number of about 600. In catalytic oxidation the reaction is continued until a comparable amount of oxygen has been consumed or absorbed but a corresponding increase in peroxide number may not be apparent.

If desired, the'oxidized alkylate of the present invention may be caustic washed as, for instance, with dilute solutions of alkali metal hydroxides to remove the foul odor of the oxidized alkylate. Caustic washing has been found to give no detrimental effect to the repelling properties of the oxidized alkylate of the present invention.

The following examples are included to further illusstrate the present invention.

EXAMPLE I Various samples of commercial odorless solvent heavy were submitted for cockroach repellency tests. Odorless solvent heavy is the fraction of the alkylate product of isobutane and butylene which boils primarily in the range of about 375 to 460 F. with a 50% point of about 395 F. The identity and results of the tests on the samples are shown in Table I.

Table I.-.-Identity of Odorless Solvent Samples In Cockroach Repellency Tests Saponi- Peroxide Bromine Relative Sample Nature of odorless solvent heavy fication number number Odor repelnumber lency Unoxidized 0 9. 5 7. 7 Portion of A treated with Naleo HA alumina 0 0.6 5. 7 Unoxidizeduu. 0 0.7 27. 0

Plirtign of O oxidized with oxygen at 100 0. without 'cata- 28. 8 382 12. 3

.v PoBtggrboi C oxidized in presence of cobalt naphtheuate at 46. 1 81. 7 6. 6 Sweet pleasant Fair 1 Samples A and C were unoxidized alkylate a-s established by their low peroxide number.

Sample D was prepared by oxidizing a portion of Sample C as follows:

Oxidation apparatus was set up and consisted of a steam jacketed glass tube approximately 36" long and 1% wide. The bottom of the tube was equipped with a removable ec ion fitted with a 50/50 standard taper joint containing ,a porous plate. Below the porous plate there was located an inlet stopcock for the introduction of oxygen and a second drain stopcock for removing the product. The top of the reactor tube was fitted to a cold water condenser by means of a 24/40 standard taper joint.

The reactor was charged with 500 grams of sample C and steam was introduced through the jacket until the reaction temperature of 100 C. was attained. Oxygen was then bubbled through the system at a rate of about 0.3 ftfi/hour. Oxidation was carried out for about 30- 40 hours to obtain a product showing a peroxide number of about 382. The course of the oxidation reaction could be followed by measuring the peroxide number of samples of the reaction mixture taken over the reaction period.

Sample E was prepared adding grams of cobalt naphthenate to 575 grams of sample C and the mixture was heated to 165 C. Oxygen was passed through the mixture at a rate of 0.5 ft. hour for a period of 6 hours. The resulting product showed the following properties: peroxide No. 31.7; saponification No. 46.1; bromine No. 6.5. The product had a sweet ester odor in contrast to d tory Chow was placed in the center of each test pan. One hundred German cockroaches were introduced into one pen and fifty American cockroach nymphs were introduced into the other.

Controlled lighting was provided during the test period. From 6:00 am. to 6:00 p.111. each day the pen was lighted by fluorescent lights suspended 18" above the pen. From 6:00 pm. until 6:00 am. the pen was in darkness and during this time the cockroaches would seek food and water. With the beginning of each light cycle the cockroaches would seek refuge from the light in the shelter cartons, unless repelled by the treated linings.

The relative repellency of the various treatments was determined by recording the number of cockroaches inhabiting each shelter at 8:00 am. each day. Counts were facilitated by removing the cartons from the test pen and immobilizing the cockroaches with CO A11 cartons and cockroaches were returned to the test pan after counting. Any dead or moribund insects were replaced each day with fresh insects,

The results of these repellency test conducted over a. period of eight days are summarized in Table 11 below.

Table II.Evaluati0n of Samples A-E for Repellency Against American and German Cockroaches [Average 1 percent of cockroaches] American German Days after treatment inhabiting shelters-.. 1 2 3 4 6 7 8 1 2 3 4 6 7 8 Sample, average percent:

Percent dead and moribund in test pan Percent dead and moribund, total 8 1 Average of two replicate tests. 7

the material prepared by oxidation of odorless solvent vheavy without catalyst (sample D).

The cockroach repellency tests were carried out according to the procedure described below.

Test insects: Adult male German cockroach,.Blatella germanica (L). Thirteen-week-old American cockroach nymphs, Periplaneta americana (L).

Test pan: The test pan consisted of a 40" x 24" x 8" stainless steel open top box, partitioned in the center to form two 20 x 24" pans. Petrolatum was applied to the walls of the pen to prevent the escape of the test insects.

Test shelter: One-half pint ice cream type cardboard containers the bottom section of which were lined with treated 15 cm. No. 2 filter papers and the lid section with 9 cm. No. 2 filter paper and an entry hole through the wall and lining of each carton was provided in the base.

Procedure.-The test samples were applied to the filter paper shelter liners by pipetting 1.3 ml. of each onto the 15 cm. discs and 0.5 ml. onto 9 cm. discs while on glass plates. When the filter paper had dried to touch,

they were pressed into the bottom and lid sections of the cardboard cartons to form a continuous treated interior surface lining. Four cartons were prepared for each test sample, two of which were used in tests conducted with German cockroaches and two with American cockroaches.

The duplicate test shelters of each treatment were placed on the floor of the respective pans in random fashion. Water and food in the form of. Purina Labora- 75' The data of Tables I and II establish that the unoxidizecl alkylate showed little, if any, repellency towards EXAMPLE II Oxidized alkylate was prepared both by oxidation in the absence of catalyst (sample F) and in the presence of a cobalt naphthenate catalyst (sample G) in accord ance with the general method of Example I and sub mitted to cockroach repellency tests. The alkylate oxi dized was prepared from isobutane and butene and boiled primarily in the range of 375 to 460 F. with a 50% point of about 395 F. and is known as odorless solvent heavy. For comparative purposes. a commercial repellent designated as X at 1% concentration in base oil (sample H) and a 2% concentrate of fatty acids extracted from alkylate in the same base oil were also tested. The fatty extract of oxidized alkylate was prepared by treating the oxidized inaterial with dilute NaOH and acidifying the aqueous alkali extract. The extract was washed with ether and the ether evaporated. The resulting acid residue was blended into the base oil at a concentration of 2%. The 2% concentrate showed a peroxide No. of 3.2, sap. No. of 5.9 and bromine No. 32.3. The material had a foul odor and was designated sample I. A summary of materials submitted for testing and the results are presented in TableIiI.

Commercial Repellent Submitted for Cockroach Repellency Tests 'Saponifl Sample Identity of sample cation Peroxide Bromine Odor Relativev number number number repellency F Odorless solvent heavy oxidized without catalyst at 100 C. for 80 hours 48. 293 7. 7 Foul-. Good; G Odorless solvent heavy oxidized with cobalt naphthenatc catalyst at 165 C. for 6 hours 50. 0 '37. 1' H Commercial repellent at 1%cone. in base'oil 1 I. A 2% concentrate of fatty acids (which were extracted from 1 oxidized odorless solvent heavy) base oil 5. 9 3. 2 p

1 2,3,4,obis-butylenc tetrahydrofurfural, a condensation product of iuriural andbutadiene.

The procedure employed for the second series'of re- 12 less'solvency heavy of Exa-mple'II' (sample-F). A 2% pellency tests was essentially the same as described preconcentrate ofcornrnerci-eil repelIentjX' (sample J) was viously for the first series of tests, excepting that the also tested. The identity ofthe materials tested-and the filter papers wetted'with the test samples were permitted lt i ed 'i fflabl V,

a to dry for 24 hours. This modification was'made to reduce the mortality rate, since the earlier test indicated..25

that the high mortality rate might be due to the presence Table Experimental Samples cock of highly volatile material in the test samples. Four' ma h Re llenc hundred adult male German cockroaches, Blatella gerc p y manica (L) were used in the test pan. Any dead or moribund cockroaches were replaced each day with fresh a insects. Results of these testsare shown in Table IV. 'Sam- .Peroxlde Relative It should be noted that Table IV also includes a test 'Idenmyofsample numben {5 2; exposure of four shelters each of samples F, H and'un- --treated shelters. The age of this shelter treatment was F Oxidized odorless solvent 293 :Foul Lewd. 21 days. ThlS separate test was run for the purpose J wheglcvygseeTfible III). H t of directly comparing the repellency ofpxidized odor- K'III 7 gi;?hd "fi;8; 3fffi 2: less solvent heavy with "sample H. This separate test L 2 m fl 466 d D clearly established that the oxidized odorless solvent f 9;;3 y mpemn e f" O heavy sample F was superior to sample H. Y 57 ;g, a g .vlg a "448 --L o -190- The data of Tables III and IV demonstrate that the ?g.i gg gfgiii non-catalytically oxidized odorless solvent heavy was flisooetenylmlcvhol! superior to the commercial'repellent X when the com- V mercial repellent was tested at a 1% concentration in 'Isooctenyl alcohol'was"added'tmsoluhilize'2;5-dimethylhexane-2,5-

base oil (sample H). The sample containing fatty acids dlhydmpemxde' Table IV.Evaluation of Samples F-I and aCommercial Repellent H for Repellency Against German Cockroaches [Average 1 percent inhabiting shelters] Days after treatment 2 3 4 5 6 7 8 15 21 Sample F 0 7.8 6.5 4.5 5.3 as 6.0 2.0 G. 1.3 10.5 10.8 16.5 11.7 19.5 30.3 25.8 H 6.0 29.7 23.0 27.2 27.3 33.2 25.3 32.0 I 81.5 39.5 24.7 27.3 25.0 22.0 22.7 32.7 Free roviugin test pan 11.2 12.5 35.0 24.5 30.7 21.5 15.7 7.5 Percent mortality 0.3 6.5 2.3 5.5 4.5 4.3 7.8 2.0

1 Average is of four replicate tests. 2 The majority or the observed mortality was fonndto be in shelters treated with'F.

derived from the oxidized odorless solvent heavy proved The procedure used for meetingthese "samples was esineffective as a repellent and indicated that the foul odor sentially identical with the procedure already described. of oxidized odorless solvent was not responsible for its Th t t was di id d i t two parts, Part I; consisted of repellcncy. a four replicate test with samples F and I, using 250 EXAMPLE HI ;,adult.male German cockroaches;Blatellagerinarticlz, .(f)

Various peroxides as concentrates in' base oil (samples Part II consisted :of atwomeplicate test with'samplesl K, .LQM) were submitted to the cockroach repellency through M, using 250 vGerman cockroaches The results tests ot Example I and'compared tothe oxidized o'dorofthese testsare summar-iz'ed inTablcVI.

"7 Table VL-Evaluation of Oxidized Odorless Solvent Heavy and Related Materials for Repellency Against German Cockroaches [Average Percent Inhablting Shelters] Table VIlI.-Evaluation of Oxidized Odorless Solvent Heavy and Related Materials for Repellency Against German Cockroaches {Average percent inhabiting shelters] Part I (avg. of 4 reps.) Test N0. 1

Days after treatment Days after treatment 2 3 4 5 6 7 3 2 3 4 5 6 8 9 15 p 10 Sample 13 29 17 12 19 16 .7 2 51 4o 29 21 17 1o 17 74 47 41 so 52 47 0 0 1 9 24 27 24 1s 19 Free roving. 3 24 42 38 29 37 P 1s 10 17 19 22 25 26 24 Percent mortality 0 4 l 12 17 Percent mortality 1 0 2 3 2 6 10 19 Part II (avg 0(2 reps.) Test No. 2

Days after treatment Days after treatment 2 3 4 5 6 7 8 2 a 4 s s s 9 15 S l Sample fi-i 74 35 16 20 16 22 12 20 I 0 4 g 7 1g 4 g 5 14 11 21 17 17 22 19" N 0 s 5 17 13 s s 14 L 9 15 20 19 19 16 17 Q 7s 65 so 49 41 4s 47 46 M 0 22 29 24 25 14 15 Percent mortality 0 0 1 s s 10 13 29 Free roving 2 17 14 20 22 25 37 Percent mortality 0 O 0 l0 5 9 8 Test No. 1 (Table VIII) indicated that the oxldlzed Tables V and VI show that the odorless solvent heavy v 25 propylene tetrammand f m t showed some repep non-catal zed oxidation) was s p rwr thehommeflenc for the first five days, but after that time sample Y a y cial repellent X when the latter was p y at J shower greater repellency. Thus, these oxldlzed peconcentration (more than the recommended concentratroleum stocks do not appear to be egective repellents tion for com e The tests also w that in comparison with oxidized odorless solvent. t t ry a y peroxides and y peroxides were mefiec- 30 Test No. 2 (Table VIII) showed that oxidized odorfive repellents, Suggesting thahlf PeIOXIde w PQ less solvent and the caustic washed oxidized odorless Si le f r t repellent Properhes 0f the OXldlZed alkylate solvent were both good repellents. This further demony were more likely peroxides of a p fi Structure strates that the acidic components, which presumably derived from the alkylate and not y PefOXide Selected were responsible for the foul odor of oxidized odorless randomly. There is also the posslblllty that other oxyl e th were t active epe1lents genated compounds contribute to repellency. The test sample Q containing isooctyl aldehyde and EXAMPLE IV cumene hydroperoxide did not show any repellency what- I soever. Therefore, no advantageous sheet was realized -Yafl0118 Samples ldenhfied Table VII below by adding aldehyde to cumene hydroperoxide since earlier sllhlected t0 the FOPkIOaCh repellency test- In P P 0 tests in Table VI showed that cumene hydroperoxide sample N an oxldlzed odorless solvent heavy havlng an 85 was i ff ti lflltlal peroxlde No. of 226 washed twice wlth equlvolume EXAMPLE V portions of 5% NaOH and then with water. The result- 7 ing product had a sweet, pleasant odor, and showed a Samples identified in Table IV below were subjected PefOXldB number of 09. Samples 0 and P were proto the cockroach repellency test described in Example I. pared by the non-catalytic oxldatlon procedure descr be in Example I. For comparison, the test on oxidized Table Identity 22 3 2; gg g for cockroach odorless solvent F and the commercial repellent X, 2% p y cone. in base oil (I) are also included. The results are s a P d R aponi eroxi e elative also Summanzed m Table Sample Identity eatlon number repel- Table VII.-Identity of Experimental Sample for Cocknumber roa h Re ellenc Tests c p y R Odorless solvent heavy oxi- 58.1 425 Good.

. dizedy ithoutI cataflizsg to a Sample Identity otsanlple Peroxide Odor Relative s ggx genuum ero 2 ple diluted to 207 12 67 Fan. number repeuency 50 by volume in odorless sol 'r H l i iii" d ditll 1o 6 1 2 5 P v ear on 0 arm on s l n- 0 oor. F gi g fi g gg ggg 293 Foul Good ation of odorl ess solvent lyst (see Table III). fjglfiQ 0/12 1 2%Xln base oil Fair. U odofl 223 10 F k N Oxidizedodorlesssolvent, 109 Sweet Good.

so eavsg OZ; 1 a heavy, whichwascauspleasant. 6%? g 2 g fg 235 3 3: V causti o waz l le o do r les s sol- 17.0 237 Good. Yacl ,p XY veltlt leavybmxidized With- 0" 0a a YS O ggfl ig f gglg figfi 575 Poor W"... Causticvi'ashtedloxidized 050; 18.7 50 D0.

- ess so ven envy, w ie 7; hours without cataa t treated g i es roy peroxi es oriq no P hi igr l gi l ll f oz ll 402 Foul peroxide number was about I hours without catalyst 3olzazlzfte5 oxidatlon without C81 ys Q 1 5 65??? g fgi 466 D0 Y odorless solvent heavy oxi- 675 Poor.

plus 1% isc-octyl aldedlzed with cobalt naphthehyde nateeatalystplus5%t-butyl v 70 perbenzoate. The test procedure was the same as already described. Two separate tests, three replicates each, were conducted 7 The tests were conducted in the same manner as de- LusinmZSO adult male German cockroaches Blatzella scribed in Example I. The test was broken down into ,a s I I ermanica (L). The results ofthese tests are resented two parts with 250 cockroaches belng used in each art P m Table VIII. of the test. The results are summarized 1n Table X.

Table X .-Summary of Cockroach Repellency Tests [Average percent inhabiting shelters] Part I Days after treatment 2 3 4 5 6 7 8 9 10 14 Avg. percent'day Shelter treatment:

0 10 19 24 19 5 22 13 24 39 12. 5 78 66 16 19 26 23 24 25 31 20 23. 4 0 14 11 21 20 7 19 20 16 23 10.9 Percent tree roving 22 10 52 36 28 63 33 41 28 16 23. 4 Percent dead and moribund 3 1 1 1 5 41 14 17 12 0 6. 8

Part II Days alter treatment 2 3 4 5 6 7 8 9 10 14 Avg. percent/day Shelter treatment:

V. 0 0 3 5 11 3 6 25 1 3 1 4.05 V. 0 7 13 27 29 4 9 8 1 6 7. 43 31 77 42 52 34 22 38 20 17 45 27. 0 Percent free roving 69 16 42 16 26 71 47 47 81 46 33. 0 Percent dead and moribund 4 3 1 0 4 32 17 21 17 0 7. 05

According to the results summarized in part I above, the oxidized odorless solvent heavy (R) was almost completely effective as a repellent. The odorless solvent sample diluted to 20% concentration by volume (S) and the odorless solvent sample oxidized to a peroxide number of only 101 (U) were about equal in repellency, but were not as effective as the undiluted sample R. The heart out obtained by distillation of odorless solvent heavy T showed poor repellency. Thus in general the active ingredient or ingredients were concentrated in the lower boiling components of the oxidized odorless solvent, especially since the higher boiling concentrate, as indicated, showed poor repellency.

Part II of the test presented in Table X above was designed in order to further evaluate the repellency oxidized odorless solvent, which was caustic treated to destroy the free acids and treated with potassium iodide to destroy most of the peroxides. The test showed that the caustic washed oxidized odorless solvent heavy V and the caustic washed sample which also had the majority of the peroxides removed (W) were almost equal in repellency. Sample Y was included in the test in order to ascertain whether or not a sample of odorless solvent heavy, which was oxidized with cobalt naphthenate catalyst, and which previously showed little repellency, could be made more repellent by the addition of an alkyl perester. The test results, however, indicated that this sample showed poor repellency.

We claim:

1. A method for producing a cockroach repellent which comprises oxidizing the alkylate product of isobutane and a C -C aliphatic monoolefin, said alkylate product boiling primarily in the range of about 100 to 460 F. through intimate contact with an oxidizing free oxygen-containing gas for a time to absorb sufficient oxygen to provide said alkylate product with a peroxide number at least about 50 up to about 600 under non-catalytic oxidation conditions, said time being up to about hours.

2. The product produced by the method of claim 1.

3. The method of claim 1 wherein the oxidation is conducted in the liquid phase and in the absence of an oxidation catalyst.

4. The method of claim 3 wherein the alkylate product has a boiling range of about 350 to 460 F.

5. A method of claim 3 wherein the oxidation is conducted for a time suflicient to provide the alkylate produced with a peroxide number of at least about 200.

6. The product produced by the method of claim 5.

7. The method of claim 5 wherein the temperature of oxidation is about 50 to 200 C.

8. A method for repelling cockroaches from an area subject to cockroach encroachment which consists essentially of applying to said area the product produced by the method of claim 1.

9. A method for repelling cockroaches from an area subject to cockroach encroachment which consists essentially of applying to said area the product produced by the method of claim 3.

10. A method for repelling cockroaches from an area subject to cockroach encroachment which consists essentially of applying to said area the product produced by the method of claim 5.

References Cited in the file of this patent UNITED STATES PATENTS 2,020,648 Hyman Nov. 12, 1935 

1. A METHOD FOR PRODUCING A COCKROACH REPELLENT WHICH COMPRISES OXIDIZING THE ALKYLATE PRODUCT OF ISOBUTANE AND A C3-C4 ALIPHATIC MONOOLEFIN, SAID ALKYLATE PRODUCT BOILING PRIMARILY IN THE RANGE OF ABOUT 100 TO 460*F. THROUGH INTIMATE CONTACT WITH AN OXIDIZING FREE OXYGEN-CONTAINING GAS FOR A TIME TO ABSORB SUFFICIENT OXYGEN TO PROVIDE SAID ALKYLATE PRODUCT WITH A PERIOXIDE NUMBER AT LEAST ABOUT 50 UP TO ABOUT 600 UNDER NON-CATALYTIC OXIDATION CONDITIONS, SAID TIME BEING UP TO ABOUT 100 HOURS. 